module Render.Debug.Pipeline
  ( Pipeline
  , allocate
  ) where

import RIO

import Control.Monad.Trans.Resource (ResourceT)
import Data.Tagged (Tagged(..))
import Vulkan.Core10 qualified as Vk
import Vulkan.Zero (zero)

import Engine.Vulkan.Pipeline qualified as Pipeline
import Engine.Vulkan.Types (HasVulkan, HasRenderPass(..), DsBindings)
import Render.Code (compileVert, compileFrag, glsl)
import Render.Debug.Model qualified as Model
import Render.DescSets.Set0 (Scene, vertexPos, instanceTransform)
import Render.DescSets.Set0.Code (set0binding0, set0binding1, set0binding2, set0binding3, set0binding5color)

type Pipeline = Pipeline.Pipeline '[Scene] Model.VertexAttrs Model.InstanceAttrs

allocate
  :: ( HasVulkan env
     , HasRenderPass renderpass
     )
  => Vk.SampleCountFlagBits
  -> Tagged Scene DsBindings
  -> renderpass
  -> ResourceT (RIO env) Pipeline
allocate :: SampleCountFlagBits
-> Tagged Scene DsBindings
-> renderpass
-> ResourceT (RIO env) Pipeline
allocate SampleCountFlagBits
multisample (Tagged DsBindings
set0) renderpass
rp = do
  (ReleaseKey
_, Pipeline
p) <- Maybe Extent2D
-> SampleCountFlagBits
-> Config '[Scene] VertexAttrs InstanceAttrs
-> renderpass
-> ResourceT (RIO env) (ReleaseKey, Pipeline)
forall env (m :: * -> *) renderpass (dsl :: [*]) vertices
       instances.
(MonadVulkan env m, MonadResource m, HasRenderPass renderpass,
 HasCallStack) =>
Maybe Extent2D
-> SampleCountFlagBits
-> Config dsl vertices instances
-> renderpass
-> m (ReleaseKey, Pipeline dsl vertices instances)
Pipeline.allocate
    Maybe Extent2D
forall a. Maybe a
Nothing
    SampleCountFlagBits
multisample
    (Config Any Any Any
forall a. Zero a => a
zero
      { $sel:cDescLayouts:Config :: Tagged '[Scene] [DsBindings]
Pipeline.cDescLayouts  = [DsBindings] -> Tagged '[Scene] [DsBindings]
forall k (s :: k) b. b -> Tagged s b
Tagged @'[Scene] [DsBindings
set0]
      , $sel:cVertexCode:Config :: Maybe ByteString
Pipeline.cVertexCode   = ByteString -> Maybe ByteString
forall a. a -> Maybe a
Just ByteString
vertCode
      , $sel:cVertexInput:Config :: SomeStruct PipelineVertexInputStateCreateInfo
Pipeline.cVertexInput  = SomeStruct PipelineVertexInputStateCreateInfo
vertexInput
      , $sel:cFragmentCode:Config :: Maybe ByteString
Pipeline.cFragmentCode = ByteString -> Maybe ByteString
forall a. a -> Maybe a
Just ByteString
fragCode
      })
    renderpass
rp
  Pipeline -> ResourceT (RIO env) Pipeline
forall (f :: * -> *) a. Applicative f => a -> f a
pure Pipeline
p
  where
    vertexInput :: SomeStruct PipelineVertexInputStateCreateInfo
vertexInput = [(VertexInputRate, [Format])]
-> SomeStruct PipelineVertexInputStateCreateInfo
Pipeline.vertexInput
      [ (VertexInputRate, [Format])
vertexPos -- vPosition
      , (VertexInputRate
Vk.VERTEX_INPUT_RATE_VERTEX,   [Format]
Model.vkVertexAttrs)
      , (VertexInputRate
Vk.VERTEX_INPUT_RATE_INSTANCE, [Format]
Model.vkInstanceTexture)
      , (VertexInputRate, [Format])
instanceTransform
      ]

vertCode :: ByteString
vertCode :: ByteString
vertCode =
  $(compileVert [glsl|
    #version 450
    #extension GL_ARB_separate_shader_objects : enable

    ${set0binding0}

    // vertexPos
    layout(location = 0) in vec3 vPosition;
    // vertexAttrs
    layout(location = 1) in vec2 vTexCoord;
    // textureParams
    layout(location = 2) in  vec4 iTextureScaleOffset;
    layout(location = 3) in  vec4 iTextureGamma;
    layout(location = 4) in ivec2 iTextureIds;

    // transformMat
    layout(location = 5) in mat4 iModel;

    layout(location = 0)      out  vec2 fTexCoord;
    layout(location = 1) flat out  vec4 fTextureGamma;
    layout(location = 2) flat out ivec2 fTextureIds;

    void main() {
      gl_Position
        = scene.projection
        * scene.view
        * iModel
        * vec4(vPosition, 1.0);

      fTexCoord     = vTexCoord * iTextureScaleOffset.st + iTextureScaleOffset.pq;
      fTextureGamma = iTextureGamma;
      fTextureIds   = iTextureIds;
    }
  |])

fragCode :: ByteString
fragCode :: ByteString
fragCode =
  $(compileFrag [glsl|
    #version 450
    #extension GL_ARB_separate_shader_objects : enable
    #extension GL_EXT_nonuniform_qualifier : enable

    ${set0binding1}
    ${set0binding2}
    ${set0binding3}
    ${set0binding5color}

    layout(location = 0)      in  vec2 fTexCoord;
    layout(location = 1) flat in  vec4 fTextureGamma;
    layout(location = 2) flat in ivec2 fTextureIds;

    layout(location = 0) out vec4 oColor;

    const int mode = 1;

    void main() {
      vec4 texel = vec4(0);

      switch(mode) {
        case 0:
          texel = vec4(fTexCoord, 0, 1);
          break;

        case 1:
          if ((fTextureIds.t < 0) || (fTextureIds.s < 0)) break;

          texel = texture(
            sampler2D(
              textures[nonuniformEXT(fTextureIds.t)],
              samplers[nonuniformEXT(fTextureIds.s)]
            ),
            fTexCoord
          );
          break;

        case 2:
          float d0 = texture(
            shadowmaps,
            vec3(fTexCoord, 0.0)
          ).x;

          float d1 = texture(
            shadowmaps,
            vec3(fTexCoord, 1.0)
          ).x;

          texel = vec4(1-d0, 0, 1-d1, 1.0);
          break;

        default:
          break;
      }

      vec3 color = pow(texel.rgb, fTextureGamma.rgb);
      float combinedAlpha = texel.a * fTextureGamma.a;

      // XXX: premultiply alpha due to additive blending
      oColor = vec4(color * combinedAlpha, combinedAlpha);
    }
  |])